In the case of distributing data to a plurality of communication devices, a data distributor distributes data using a broadcast distribution service provided in a network managed by a carrier. To achieve the broadcast distribution, techniques such as a broadcast service and a multicast service are used. In mobile communication networks, CBS (Cell Broadcast Service) is used to distribute emergency information. CBS is a service that sends a notification about emergency information by broadcasting to mobile phone terminals within a target area for distribution of emergency information. Further, ETWS (Earthquake and Tsunami Warning System) is provided to meet the need for high-speed disaster notification and a flexible distribution area.
Patent Literature 1 discloses a configuration in which a distribution area is designated in a broader-area unit or a sector unit in the case of designating a distribution area for an emergency message.